This invention relates to a molding machine and more particularly to an automatic matchplate molding machine of the type in which a pattern plate is located between cope and drag flasks adapted to be filled with sand and adapted to be rammed upwardly toward a squeeze head in order to pack the sand and form cope and drag molds in the cope and drag flasks, respectively. A machine of this general type is disclosed in Hunter U.S. Pat. No. 4,840,218.
The pattern plate of such a machine carries an upwardly projecting sprue former which forms a sprue in the cope mold. Coacting with the sprue former is a basin former which creates a pouring basin in the upper side of the cope mold around the sprue. The basin former is carried by the squeeze head and telescopically receives the sprue former when the cope flask and the pattern plate are rammed upwardly toward the squeeze head. When the two formers are telescoped together, a small sand core may be created in the basin former and may fall downwardly into the pouring basin and the sprue when the cope flask and the cope mold are retracted downwardly from the squeeze head.
To prevent loose sand from falling downwardly when the cope flask and cope mold are retracted, a one-piece plastic liner with means for injecting pressurized air through the side of the liner has been employed to blow sand in the basin former out of the upper end thereof and away from the mold. A liner of this type is disclosed in Hunter U.S. Pat. No. 5,069,268. During operation, the liner telescopically receives the sprue former and, as a result of repeated sliding of the sprue former within the liner, the latter wears and eventually must be replaced. The one-piece liner of the '268 patent is comparatively large and thus is relatively expensive to replace.